Synthesis of trifunctional thioureas bearing 1,5-disubstituted triazole tether by Ru-catalyzed Huisgen cycloaddition

Synthesis of trifunctional thiourea catalysts tethered with a variety of functional group is described. 1,5-Triazole tether in the catalysts was constructed by ruthenium-catalyzed Huisgen cycloaddition. We demonstrate the utility of the synthetic thioureas as an asymmetric catalyst for Michal addition of nitrostyrene with cyclohexanone.